nick49

My car is stock, '04. I got .9 bar for a couple of seconds, with camera in my right hand after making a shift I put it up to my eye and tried to take a pic. I fired off a few shots but could only get a pic of .8 bar. This is between turns in a canyon with a 45 mph limit at 6k' elevation.

I may be totally wrong, often am. I thought as you went up in elevation the effective boost pressure dropped as well. Lower elevations have denser air and cranking pressures are higher on na motors with the same compression than here a few thousand feet up. I had a PPI done by a well respected race shop in Florida and they got a solid 1 bar on an '05 X50 and reported that was as it should be. My brother could not get any more than about .7 out of his X50 '04 stock 996 here at 5k'.

I'm totally open to correction as I'm assuming and don't know.

SSST

Come down to the Gulf coast and try to get .8 on a stock tune. The air is denser with O2 down here and waste gates kick in. I did see .8 once, but that was in the hill country at about 2000 feet on a 60 degree day.

Macster

You managed to get 0.9 bar boost at around 6K feet above sea level and I suspect on a mild day.

Not unusual. In fact, what you report agrees with what I've been told and what I later confirmed in some fashion.

What I've been told is the DME will attempt to satisfy the torque demand of the driver, as long as it can do so and stay within the limits of engine operation.

What can happen is under some conditions -- elevation is one -- is under hard/extreme acceleration the boost can climb over the 0.7 bar to 0.8 bar even 0.9 bar maybe higher (1.0 bar?) but I've never seen anything over 0.9 bar.

The most I've seen is 0.9 bar and this remained in effect long enough to get a pic of it with my camera which was difficult because the car was accelerating like crazy. (God I love my Turbo!).

Oh, this 0.9 bar occurred at quite a few hundred feet over 8K elevation (on I-80 somewhere in Wyoming) and in cold dry air, cold enough patches of snow were on the ground.

At sea level, even in cold air, the most boost I've ever seen is 0.7 bar.

I have no experience with the X50 cars and no experience with mod'd cars and what boost levels they can produce.

Sincerely,

Macster.

Speedyellow993

Lol! That's a good one.

2nd gear pop out....safely throttle on in turn, followed by a quick throttle lift then back on and lift throttle. This usually does it.

GL

an02boxster

Well I bought the car. 46k miles, feel very tight. I do all of my own repairs so I did the PPI myself at the point of sale, they had a lift...
The NSX is a friends that just got a turbo installed its fast but I can pass him in the corners.
Here are the pics:

Speedyellow993

Sweet looking car ;-D

Just wait until the mods start on the 6t. Mrs. NSX won't be passing you anywhere. Not to mention a Turbo NSX is worth about 15 laps at the track before everything overheats. The 996tt.... You can track it all day long!!!

Kevinmacd

My stock 996tt gets .8 bar here in Fla. No tune and it's not an X50

bmwtmx

Where are all these Florida people located? I'm doing a PPI on a 2001 next week and if all checks out will have it in 2 weeks!

doubleurx

FWIW: I live at 6500 feet and stock my car saw 0.7 bar at WOT. The only time I saw 0.8 was right at throttle lift for the next shift. Now it is tuned and sees 1.0 bar sustained at WOT with 1.1-1.2 at throttle lift.

Macster

The boost drops off as the rpms climb. IOWs, max boost occurs at something less than redline. I can't recall now the boost curve.

I do remember when I was testing to see what the boost reading would reach I gave the engine max throttle at just under 3K rpms and in a higher gear to prolong the amount of time the engine rpms stayed on the max boost spot.

The techs tell me the DME/throttle will attempt to satisfy the torque demanded by the driver. If the torque demand can be met with less than max boost (nominally 0.7 bar) that's what happens.

In some cases -- operating at altitude based on my experience -- the boost will be allowed to go higher. I do not know what the upper limit is under the most ideal conditions for maximizing boost. One of these days I will drive on I-70 through some high passes (there are IIRC a couple at around 11K feet) and see if I can get the boost to go to 1.0bar.

Or perhaps I will make a side trip to Pike's Peak and try the car out at over 11K feet. I believe Pike's Peak is the highest paved road in the 48 states.

Sincerely,

Macster.

an02boxster

I am in Bradenton, FL just south of Tampa Bay and north of Sarasota

SiFi1886

Nice ride. Congrats.

Do you have any mods planned?

an02boxster

Would like to lower the ride height to what 99 C4 is with the ROW 030. Because I think it looks so much better, I am happy with the stock handling, any suggestions that doesn't cost thousands?
No engine mods planned but it did come with some really well made SS headers.
Looking for some nice trim pieces for dash.
The car is an incredible upgrade from the C4 so I am very happy.
Looking at tires trying to decide what to put on.
And thanks for the nice comments.

"02996ttx50

congrats on the car! looks great. coming from a n/a pcar the turbo will astound you. i wanted to suggest that if you took the shot of your spoiler "up" you might want to forgo that in the future as that will ( in my experience ) accelerate the potential for spoiler ram/hydraulics(s) issues. problems with them are peculiar to this iteration of the tt, and the stories of "failure" are legion. btw, anyone tries to tell you differently? just don't listen.

as to the lowering, i think you're right to mod even without engine performance stuff, and for a very low price point, you might want to consider simply putting on some H&R "sport" springs for about $350.00. best bang for the buck. they will lower your car to roughly to ROW height ( maybe 40mm? ) and give you an aggressive stance, and stiffer ride which helps when pushing the car in twists etc. if i did nothing else to my car, tweaking the stock suspension would be it.

as to tires? i've tried many but always go back to ( well, i dont try others any more.. ) ps2's. i won't skimp on rubber at the speeds this car is capable of.

good luck, drive it in good health.. and get ready for maintenance costs. i.e. "the joy of ownership"

Kevinmacd

Try the Hankook Ventus V12, they are outstanding tires for the price. Michelins are over priced, and the Hankooks have more sidewall plies. C&D did a test on these tires and were very impressed
http://www.caranddriver.com/comparis...12-evo-page-10